Finding songs with explicit lyrics

Hello there, I am in the process of identifying all songs with explicit lyrics and adding a tag so that I can identify these easily.

I have run a program which has added lyrics to id3 tags.

Now I want to use mp3tag to find the files with explicit words in them. I thought this would be easy, either by doing a word at a time or having a word list.

However, running what I think is the correct filter includes songs without that particular word/list:

UNSYNCEDLYRICS HAS "example"

Is this wrong? Can someone please tell me why mp3tag is finding songs without a particular result in the list of filtered songs?

I don't know because I neither see the concrete filter term nor the data in the alleged false hits.